The role of Analytical Core D will be to provide essential analytical measurements in support of all Projects and Cores of the UIC Botanical Center. Three types of measurements are proposed including structure elucidation (Specific Aim 1), quantitative analysis (Specific Aim 2) and MS-based screening (Specific Aim 3). Structure elucidation of botanical natural products, their degradation products and their human metabolites will benefit all three Projects and Cores and will include high resolution accurate mass measurement mass spectrometry, tandem mass spectrometry (MS/MS), 1-D and 2-D 1H-NMR and 13C-NMR. Facilities for these measurements include Orbitrap, FT-ICR, ion trap-ToF, quadrupole-ToF, ion trap, MALDI-ToF, and triple quadruple mass spectrometers as well as 400 MHz, 600 MHz, 800 MHz, and 900 MHz NMR instruments. Quantitative analysis of botanical constituents, their human metabolites, biomarkers of efficacy or toxicity, and probe substrates for clinical studies of drug-botanical interactions will benefit all Projects and Cores. These quantitative measurements will rely on either ultrahigh pressure liquid chromatography-tandem mass spectrometry (UHPLC- MS/MS), especially for trace analysis and measurements of multiple species in complex biological samples, or qNMR, which will be especially helpful for purity analyses of analytical standards. The use of UHPLC in place of HPLC will enhance separation efficiencies and increase productivity by shortening the time required for chromatographic separations during UHPLC-MS/MS. In support of mechanism of action studies and the bioassays of Core C and Project 2, mass spectrometry-based screening assays will be carried out. These assays will include the development of assays for new targets as required as well as applications of our existing assays, which are based on pulsed ultrafiltration-MS (invented in this laboratory) for ligands to targets such as the estrogen receptors and our assay for natural products that up-regulate the antioxidant response element through the Keap1/Nrf2 pathway. In summary, Analytical Core D will provide MS and NMR measurements and analytical expertise to enhance the productivity of all Projects and Cores of the UIC Botanical Center.